Classifications

• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C303/00—Preparation of esters or amides of sulfuric acids; Preparation of sulfonic acids or of their esters, halides, anhydrides or amides
  • C07C303/32—Preparation of esters or amides of sulfuric acids; Preparation of sulfonic acids or of their esters, halides, anhydrides or amides of salts of sulfonic acids
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C303/00—Preparation of esters or amides of sulfuric acids; Preparation of sulfonic acids or of their esters, halides, anhydrides or amides
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C303/00—Preparation of esters or amides of sulfuric acids; Preparation of sulfonic acids or of their esters, halides, anhydrides or amides
  • C07C303/02—Preparation of esters or amides of sulfuric acids; Preparation of sulfonic acids or of their esters, halides, anhydrides or amides of sulfonic acids or halides thereof
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C303/00—Preparation of esters or amides of sulfuric acids; Preparation of sulfonic acids or of their esters, halides, anhydrides or amides
  • C07C303/02—Preparation of esters or amides of sulfuric acids; Preparation of sulfonic acids or of their esters, halides, anhydrides or amides of sulfonic acids or halides thereof
  • C07C303/22—Preparation of esters or amides of sulfuric acids; Preparation of sulfonic acids or of their esters, halides, anhydrides or amides of sulfonic acids or halides thereof from sulfonic acids, by reactions not involving the formation of sulfo or halosulfonyl groups; from sulfonic halides by reactions not involving the formation of halosulfonyl groups
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C313/00—Sulfinic acids; Sulfenic acids; Halides, esters or anhydrides thereof; Amides of sulfinic or sulfenic acids, i.e. compounds having singly-bound oxygen atoms of sulfinic or sulfenic groups replaced by nitrogen atoms, not being part of nitro or nitroso groups
  • C07C313/02—Sulfinic acids; Derivatives thereof
  • C07C313/04—Sulfinic acids; Esters thereof

Definitions

• the subject of the present invention is a new process for the preparation of oxysulfide and fluorinated derivatives implementing an oxidation reaction in the presence of an organic solvent.
• the invention more particularly relates to the preparation of perfluoroalkanesulphonic acids, in particular trifluoromethanesulphonic acid.
• Perhaloalkanesulfonic acids and more particularly trifluoromethanesulfonic acid, better known under the name "trifiic acid", are used as catalysts or as intermediates in organic synthesis.
• an alkali metal salt, generally of potassium, of trifluoromethanesulfinic acid is synthesized by sulfation reaction from a trifluoromethanecarboxylic acid salt, in an aprotic organic solvent, typically N, N-dimethylformamide (DMF).
• an aprotic organic solvent typically N, N-dimethylformamide (DMF).
• the trifluoromethanesulfonic acid salt is oxidized in an aqueous medium, generally with hydrogen peroxide, to a trifluoromethanesulphonic acid salt, which, after acidification, will lead to trific acid.
• the preparation of trifiic acid is described, for example, in EP 0 396 458 and EP 0 735 023.
• the present invention aims at providing a new process for the preparation of oxysulfide and fluorinated derivatives, in particular useful for the synthesis of trifluoromethanesulfonic acid, and not having the drawbacks mentioned above. More specifically, the present invention relates, according to a first aspect, to a process for the preparation of an oxysulphurized and fluorinated derivative of formula (III)
• Ea representing the fluorine atom or a group having 1 to 10 carbon atoms selected from fluoroalkyls, perfluoroalkyls and fluoroalkenyls;
• R representing hydrogen, a monovalent cation or an alkyl group
• the inventors have shown that the oxidation can be carried out in an organic solvent to access the desired oxysulfide and fluorinated derivative, in particular potassium trifluoromethanesulfonate, with performances in terms of kinetics and selectivity at least identical to those an oxidation to an aqueous solvent.
• the sulfation and oxidation steps according to the invention for example to access potassium trifluoromethanesulphonate from potassium trifluoromethanecarboxylate, can be carried out in a single polar aprotic organic solvent so that these steps can be carried out successively and without intermediate step of switching solvents, in particular within the same reactor.
• the method of the invention advantageously allows a saving of time, and therefore a reduction in cost, due to the reduction in the number of steps required to obtain potassium trifluoromethanesulphonate (and triflic acid). ) for example.
• sequence of sulfation and oxidation steps according to the invention in polar aprotic organic solvent medium minimizes the degradation of the reaction stream from sulfmation, which can occur during the switching of solvents.
• the implementation of the process of the invention makes it possible to improve the overall yield of the preparation of potassium trifluoromethanesulfonate (and triflic acid).
• the method of the invention by not using aqueous solvent, provides access to electronic grade triflic acid, having a low sulfate content, or even being free of sulfates.
• the process of the invention is not limited to the sole synthesis of potassium trifluoromethanesulfonate and that of triflic acid.
• the process for preparing an oxysulfurized and fluorinated derivative of formula Ea-SO 3 R (III) according to the invention involves an oxidation reaction of an Ea-SOOR (II) compound with an agent oxidant, in an organic solvent medium.
• solvent is intended to mean a compound which is liquid at its temperature of use and which, because of its content in the reaction medium, is capable of solubilizing a reagent.
• the organic solvent used is more particularly capable of solubilizing the compound of formula (II).
• the reaction medium of the oxidation reaction according to the invention is free of aqueous solvent.
• the reaction medium may comprise a water content of less than or equal to 10% by weight, in particular less than or equal to 4% by weight, or even be free of water.
• the water content may be less than 100 ppm.
• These small amounts of water may more particularly come from the oxidizing agent used for the oxidation reaction, for example hydrogen peroxide, and / or be formed by the oxidation reaction.
• reaction medium means the medium in which the chemical reaction concerned takes place, in this case the oxidation reaction.
• the reaction medium comprises the reaction solvent (organic solvent in the case of the oxidation reaction according to the invention) and, depending on the progress of the reaction, the reactants and / or the products of the reaction. It may further comprise additives and impurities.
• solvent means a single solvent or a mixture of solvents.
• the organic solvent used in the invention may be an organic solvent or a mixture of two or more organic solvents. In the case of a mixture, the solvents may be miscible or immiscible with each other.
• the organic solvent is a polar aprotic solvent.
• aprotic solvent a solvent which, according to Lewis's theory, has no protons to release.
• the organic solvent used for the oxidation reaction according to the invention may be more particularly the solvent used for the formation of the compound of formula (II) by sulfation from a compound of Ea-COOR formula (I).
• the organic solvent is polar. It is thus preferable for the polar aprotic solvent used according to the invention to have a significant dipole moment.
• its relative dielectric constant ⁇ is advantageously at least equal to 5.
• its dielectric constant is less than or equal to 50 and greater. or to 5, in particular between 30 and 40.
• the solvents used in the process of the invention are capable of solvating the cations well, which means that the solvent has certain properties of Lewis basicity.
• its basicity is assessed by reference to the "donor number".
• a polar organic solvent is chosen having a donor number greater than 10, preferably greater than or equal to 20. The upper limit is not critical.
• An organic solvent having a donor number between 10 and 30 is preferably chosen. It will be recalled that the "donor number" or “donor number” abbreviated DN, gives an indication of the nucleophilic character of the solvent and reveals its ability to give its doublet.
• the polar solvent or solvents do not exhibit acidic hydrogen, in particular when the polar nature of the solvent (s) is obtained by the presence of electron-withdrawing groups, it is desirable that there is not of hydrogen on the atom in position a of the electro-attracting function.
• the pKa corresponding to the first acidity of the solvent is at least about 20 ("about" underlining that only the first digit is significant), preferably at least about 25, preferably included between 25 and 35.
• the acid character can also be expressed by the acceptor index AN of the solvent, as defined by Christian REICHARDT, ["Solvents and solvent effects in Organic Chemistry", 2nd edition, VCH (Federal Republic of Germany), 1990, pages 23 -24].
• this acceptor index AN is less than 20, in particular less than 18.
• the organic solvent is of the amide type.
• amides of particular character, such as tetrasubstituted ureas and monosubstituted lactams, are also included.
• the amides are preferably substituted (disubstituted for ordinary amides).
• the organic solvent may be more particularly chosen from N, N-dimethylformamide (DMF), ⁇ , ⁇ -diethylformamide (DEF), N, N-dimethylacetamide (DMAC), pyrrolidone derivatives such as N-methylpyrrolidone ( NMP) and mixtures thereof.
• DMF N-dimethylformamide
• DEF ⁇ , ⁇ -diethylformamide
• DMAC N-dimethylacetamide
• NMP N-methylpyrrolidone
• ethers are particularly interesting categories of solvent, whether symmetrical or unsymmetrical, whether open or not.
• ethers must be incorporated the various derivatives of glycol ethers such as different glymes, for example diglyme.
• the organic solvent used for the oxidation reaction according to the invention is DMF.
• the oxidizing agent may be chosen from peroxides, peracids and their salts.
• the oxidizing agent may be chosen from hydrogen peroxide; percarbonates, especially sodium or potassium percarbonate; persulfates including potassium persulfate; persulfuric acid, for example Caro salt; and organic peroxides, for example hydrogen peroxide-urea.
• the oxidizing agent may be miscible or not in the reaction medium.
• the reaction medium may be homogeneous or heterogeneous.
• the oxidizing agent is anhydrous.
• the oxidizing agent is hydrogen peroxide.
• Hydrogen peroxide can have a concentration in the water of between 10% and
• the oxidizing agent may be chosen from gaseous agents, for example from the group consisting of air, oxygen (O 2 ), ozone (O 3 ) and nitrous oxide (N 2 0).
• gaseous agents for example from the group consisting of air, oxygen (O 2 ), ozone (O 3 ) and nitrous oxide (N 2 0).
• O 2 oxygen
• O 3 ozone
• N 2 0 nitrous oxide
• the oxidation with these agents may possibly be carried out in the presence of a metal catalyst.
• At least one compound of formula Ea-SOOR (II) is reacted with an oxidizing agent.
• Said compound of formula (II) may be a fluorosulfinic acid (R represents a hydrogen atom in formula (II) above), a fluorosulfinic acid salt (R represents a monovalent cation in formula (II) above) or a fluorosulfinic acid ester (R represents an alkyl group in formula (II) above, in particular an alkyl group having from 1 to 10 carbon atoms).
• fluorosulfonic acid (R represents a hydrogen atom in the formula (III) above), a fluorosulfonic acid salt (R represents a monovalent cation in the aforementioned formula (III)) or a fluorosulfonic acid ester (R represents an alkyl group in the aforementioned formula (III), in particular an alkyl group having from 1 to 10 carbon atoms).
• said compound of formula (II) is a fluorosulfinic acid salt in which R represents a monovalent cation advantageously chosen from alkaline cations, quaternary ammonium and quaternary phosphonium cations.
• the ammonium or quaternary phosphonium cations may more preferably be chosen from tetraalkylammonium or phosphonium, trialkylbenzylammonium or phosphonium, tetraarylammonium or phosphonium, whose alkyl groups, which may be identical or different, represent a linear or branched alkyl chain having from 4 to 12 carbon atoms. carbon, preferably from 4 to 6 carbon atoms and the aryl group is preferably a phenyl group.
• it is the tetrabutylphosphonium cation.
• R represents an alkaline cation, in particular chosen from sodium, potassium, cesium and rubidium cations.
• R is the potassium cation.
• the group Ea may represent the fluorine atom or a group having from 1 to 10 carbon atoms chosen from fluoroalkyls, perfluoroalkyls and fluoroalkenyls.
• alkyl a linear or branched hydrocarbon-based chain preferably comprising from 1 to 10 carbon atoms, in particular from 1 to 4 carbon atoms;
• fluoroalkyl a group formed by a linear or branched C1-C10 hydrocarbon-based chain containing at least one fluorine atom
• perfluoroalkyl a group consisting of a linear or branched C1-C10 chain comprising only fluorine atoms, in addition to carbon atoms, and devoid of a hydrogen atom;
• fluoroalkenyl a group formed by a linear or branched C 1 -C 10 hydrocarbon-based chain containing at least one fluorine atom and comprising at least one double bond.
• the group Ea is chosen from the fluorine atom and a group having from 1 to 5 carbon atoms chosen from fluoroalkyls, perfluoroalkyls and fluoroalkenyls.
• the group Ea in the compound of formula (II) is chosen from fluorine atom, CH 2 F radical, CHF 2 radical, C 2 F 5 radical and CF 3 radical. .
• the result thus respectively the preparation according to the method of the invention F-SO3R, CH 2 F, S0 3 R, of CHF2-SO3R, C 2 F 5 -S0 3 R and CF 3 -SO 3 R where R is as previously defined.
• Ea represents the radical CF 3 . It is understood that the above-mentioned definitions for groups R and Ea respectively can be combined.
• the method of the invention implements a compound of formula Ea-SOOR (II), in which:
• Ea is chosen from fluorine atom, CH 2 F radical, CHF 2 radical and CF 3 radical; in particular Ea is the radical CF 3 ; and
• R represents an alkaline cation, preferably the potassium cation.
• the process of the invention may be more particularly carried out for the preparation of an alkali metal salt of trifluoromethanesulphonate (CF 3 SO 3 R with R representing an alkaline cation), in particular potassium trifluoromethylsulphonate (CF 3 SO 3 K, or potassium triflate), which may advantageously be used to access triflic acid (CF 3 SO 3 H) or triflic anhydride ((CF 3 SO 2 ) 2 O), as detailed in the rest of the text.
• CF 3 SO 3 H trifluoromethanesulphonate
• CF 3 SO 2 triflic anhydride
• Those skilled in the art are able to adapt the conditions for carrying out the oxidation reaction in the organic solvent to yield the desired oxysulfide and fluorinated derivative of formula (III).
• the bringing into contact of the compound of formula (II) with an oxidizing agent is carried out under conditions conducive to the formation of the derivative of formula (III).
• the contacting of the compound of formula (II) with the oxidizing agent may be carried out continuously, semi-continuously or discontinuously (batch). Preferably, it is carried out semi-continuously (semi-batch). In the case of a semi-continuous process, it is the oxidizing agent that can be introduced continuously into the reaction medium.
• the process according to the invention can be carried out in an apparatus allowing a semi-continuous or continuous implementation, for example in a perfectly stirred reactor, a cascade of perfectly stirred reactors advantageously equipped with a double jacket or a tubular reactor equipped with a jacket in which circulates a coolant.
• the oxidizing agent for example hydrogen peroxide
• the oxidizing agent can be added continuously in a liquid medium, previously prepared, comprising said compound of formula (II) in the organic solvent.
• the concentration of compound of formula (II) in the organic solvent in the initial reaction medium is between 1% and 40% by weight, in particular between 5% and 30% by weight.
• the oxidation reaction according to the process of the invention can be carried out by bringing the reaction medium to a temperature of between 20 ° C. and the boiling point of the organic solvent, in particular between 40 ° C. and 140 ° C.
• the oxidizing agent can be added after having previously heated the liquid medium comprising the compound of formula (II) in the organic solvent.
• the duration of the heating can be adjusted according to the chosen reaction temperature. It can be between 30 minutes and 24 hours, in particular between 1 hour and 20 hours, and more particularly between 2 hours and 7 hours.
• the progress of the oxidation reaction can be followed by an analytical method.
• the progress of the oxidation reaction for example the concentration of compound of formula (II), can be monitored online (via a sampling loop for example) or in situ by RAMAN spectrometry, by near infrared spectrometry or by UV spectroscopy, preferably by RAMAN spectrometry.
• the reactor in which the oxidation reaction takes place can be equipped with a Raman probe, connected by an optical fiber to the Raman spectrometer, said probe allowing for example to follow in the medium the concentration of compound of formula (II).
• the compound of formula Ea-SOOR (II) used for the oxidation reaction according to the process of the invention may be prepared beforehand from the reaction, in the presence of an organic solvent, of a compound of formula Ea-COOR (I), where Ea and R are as defined above, with a sulfur oxide (sulfation reaction).
• the present invention relates, in another of its aspects, to a process for the preparation of an oxysulphurized and fluorinated derivative of formula (III):
• Ea representing the fluorine atom or a group having 1 to 10 carbon atoms selected from fluoroalkyls, perfluoroalkyls and fluoroalkenyls;
• R representing hydrogen, a monovalent cation or an alkyl group
• step (ii) adding to the reaction mixture obtained at the end of step (i) of sulfinating an oxidizing agent, to obtain the derivative of formula (III).
• the organic solvent may be more particularly as defined above. It may be preferably ⁇ , ⁇ -dimethylformamide (DMF).
• the reaction medium of steps (i) and (ii) comprises a water content less than or equal to 10% by weight, in particular less than or equal to 4% by weight, or even is free of water.
• the small amounts of water of the reaction medium come from the oxidizing agent in the case of a hydrated oxidizing agent such as hydrogen peroxide, or water produced by oxidation-reduction during the reaction of the oxidizing agent. 'oxidation.
• the sulphination reaction is known and already described, for example, in EP 0 735 023. Those skilled in the art are able to adjust the conditions for carrying out the sulphidation step (i).
• the bringing into contact of the compound of formula (I) with a sulfur oxide is conducted under conditions conducive to the formation of the derivative of formula (II).
• step (i) of sulfinating the process of the invention it is desirable to control the content of impurities present in the reaction medium.
• the content of labile hydrogen atoms of the sulfination reaction medium (step (i)), or more exactly of the releasable protons carried by its various components, including their impurities, must be less than the content of fluorinated groups released. by decomposition of the compound of formula (I).
• labile hydrogen atom or releasable proton is meant a hydrogen atom that is likely to be torn off as a proton by a strong base. In practice, these are protons of acidic functions that have a pKa of less than about 20. The Releasable protons will be low, the less chance there is of parasitic reaction and the better will be the sulfation yield.
• the content of releasable protons present in the medium is at most equal to 20% of the initial concentration of said compound of formula (I).
• this content is at most equal to 10%, preferably 1% (in moles), relative to the initial content of compound of formula (I).
• the main molecule carrying labile hydrogen atoms is usually water which is capable of releasing up to two protons per molecule.
• water which is capable of releasing up to two protons per molecule.
• reagents and dehydrated solvents so that the water content of each of the reagents is at most equal to 1 per 1000, relative to the total mass of said reagent. .
• water contents may be satisfactory, but in some cases it may be advantageous to operate at lower levels, for example of the order of 1 per 10,000.
• the metal impurities be in small amounts.
• Metallic elements may be present as impurities provided in particular by the reagents, the solvent or by metal equipment following corrosion.
• the compound of formula (I) is a fluorocarboxylic acid salt, it is prepared by reacting a base with the corresponding fluorocarboxylic acid. under conditions such that the base is introduced in an amount close to ⁇ 5%, and preferably equal to the stoichiometric amount.
• the two classes of metals that can be essentially present namely the two-valence transition elements (such as copper, iron or chromium) and the elements of the column VIII (in particular platinum group metals consisting of platinum, osmium, iridium, palladium, rhodium and ruthenium) must be present in the medium at a level expressed relative to with fluorocarboxylic acid at most equal to 1000 ppm molar, preferably 10 ppm molar.
• the compound of formula Ea-COOR (I) used in stage (i) can be wholly or partly a recycled compound, which can be obtained for example by separation at the end of the oxidation reaction or which can come from of a subsequent synthesis step, for example by separation after the preparation of a fluorinated derivative sulfonic acid or a fluorinated compound having an anhydride function of the sulfonic acid, as detailed in the following text.
• the compound of formula Ea-COOR (I) used in step (i) is a salt, that is to say when R represents a monovalent cation, said salt may have been obtained by salifcation of the corresponding acid. that is to say the compound of formula Ea-COOR (I) in which R represents a hydrogen atom.
• the compound of formula (I) is an alkali metal salt of trifluorocarboxylic acid, in particular potassium trifluoroacetate, it may have been obtained by salifcation of the corresponding trifluorocarboxylic acid, in particular trifluoroacetic acid.
• the salifunction agent may conventionally be chosen from inorganic or organic bases, in particular from the hydroxides, carbonates and alkoxides of a monovalent cation.
• the monovalent cation may advantageously be chosen from alkaline cations, in particular sodium, potassium, cesium and rubidium, more particularly potassium.
• the base may be selected from the group consisting of potassium hydroxide and sodium hydroxide, and most preferably it is potassium hydroxide.
• the mixture between the acid and the salt-forming agent can be carried out according to any means known to those skilled in the art.
• a mixing device can be suitably selected from different classes of mixers, for example stirred reactors, external recirculation loop reactors and dynamic mixers.
• an intensified mixing system can be used.
• the mixing means may preferentially be chosen from impact jet mixers, coaxial nozzle injectors and Venturi tubes, optionally supplemented with Sulzer or Kenics type static mixers.
• the intensified mixing method advantageously makes it possible to put the reactants in contact continuously in an efficient manner.
• the reaction volume can be minimized while intensifying the mixing conditions.
• the evacuation of the enthalpy reaction is accelerated, which limits the temperature rise and allows the use of plastic materials more resistant to corrosion phenomena than conventional metals (stainless steel, nickel-base steel). This technology can advantageously lead to a more economical and more productive process.
• the sulfur oxide may be more particularly sulfur dioxide. It is usually implemented in gaseous form. It can also be introduced under solution form, in the organic solvent chosen for the reaction, at a concentration generally ranging between 1% and 10% by weight, preferably between 3% and 6% by weight.
• the sulphination step (i) is carried out with an initial molar ratio of sulfur oxide / compound of formula (I) of less than 0.4, in particular less than 0.2, and with a concentration of sulfur oxide dissolved in the reaction medium kept constant throughout the duration of the reaction at a value between 0.2 and 3% by weight.
• Maintaining a constant concentration of sulfur oxide in the reaction medium can be implemented by a controlled and continuous addition of sulfur oxide to the reaction medium.
• concentration may vary by ⁇ 20%, preferably by ⁇ 10%.
• the monitoring of the dissolved sulfur oxide concentration in the reaction medium can be ensured by an analytical method, as described above, in particular by RAMAN spectrometry.
• the controlled addition of sulfur oxide to the reaction medium advantageously makes it possible to convert the compound of formula (I) into a compound of formula (II) while substantially disadvantaging the parasitic chemistry related to the degradation of the compound of formula (I ) by sulfur oxide.
• the concentration of the compound of formula (I) in the organic solvent in the initial reaction medium of step (i) can be between 1 and 40% by weight, in particular between 5 and 30%. in weight.
• the contacting of the compound of formula (I) with the sulfur oxide in step (i) of the process of the invention may be carried out continuously or semi-continuously (or semi-batchwise). Preferably, it is carried out semi-continuously, in particular in an apparatus as described above for the oxidation process according to the invention.
• the compound of formula (I) can be introduced integrally into the organic solvent, and then the sulfur oxide is added continuously.
• the sulfur oxide is added after having previously heated the solution formed of the organic solvent and the compound of formula (I) at a temperature between 50 ° C and 150 ° C.
• silica is introduced into the reaction medium, preferably in an amount such that it represents from 0.1 to 10% by weight, preferably from 0.5 to 10% by weight in the reaction medium.
• the silica is added to the solution formed of the organic solvent and the compound of formula (I) when the process according to the invention is carried out semi-continuously.
• the addition of silica makes it possible to substantially reduce the corrosive impact on the reactor of the fluorides generated in the medium by the implementation of the sulfination step according to the invention.
• the sulfination reaction according to step (i) of the process of the invention can be carried out by bringing the reaction medium to a temperature of between 100 ° C. and 200 ° C., in particular between 120 ° C. and 160 ° C.
• the sulfidation reaction is advantageously carried out at atmospheric pressure, but higher pressures can also be used.
• an absolute total pressure chosen between 1 and 20 bar and preferably between 1 and 3 bar may be suitable.
• the reaction can be carried out at a pressure below atmospheric pressure.
• the absolute total pressure may be between 1 mbar and 999 mbar, in particular between 500 mbar and 950 mbar, and more particularly between 800 mbar and 900 mbar.
• the duration of the heating can be adjusted according to the chosen reaction temperature. It can be between 30 minutes and 24 hours, in particular between 1 hour and 20 hours and more particularly between 2 hours and 7 hours.
• the average residence time which is defined as the ratio between the volume of the reaction mass and the feed rate, is more particularly between 30 minutes and 10 hours, and in particular between 2 hours and 4 hours.
• the progress of the reaction can be controlled by the degree of conversion of the compound of formula (I), which designates the ratio between the molar amount of compound of formula (I) consumed during the reaction on the total amount of formula
• the sulphination step (i) is carried out until a conversion rate of said compound of formula (I) ranging from 50% to 100%, in particular from 55% to 90%, is obtained. %>.
• the reaction medium thus generally comprises a mixture of the compound formed Ea-SOOR (II) and the compound Ea-COOR (I) unconsumed.
• an oxidizing agent is added to the reaction medium to form by oxidation reaction with the compound of formula Ea-SOOR (II), the desired derivative of formula Ea-SO 3 R (III).
• the reaction medium obtained at the end of the oxidation step (ii) generally comprises a mixture of the oxysulphurized and fluorinated derivative of formula Ea-SO 3 R (III) and of the non-consumed starting compound Ea-COOR (I). .
• the latter can be advantageously isolated and recycled, for example used in step (i) of the method according to the invention.
• steps (i) and (ii) can be conducted in the same reactor in semi-continuous mode.
• steps (i) and (ii) can be conducted in two tubular reactors in series.
• the process of the invention makes it possible to prepare a fluorosulfonic acid salt from a fluorocarboxylic acid salt.
• CF 3 SO 3 R with R representing an alkaline cation
• CF3SO3K potassium trifluoromethylsulfonate
• the latter can advantageously be used to access triflic acid (CF 3 SO 3 H) or triflic anhydride ((CF 3 S0 2 ) 2 0), as detailed in the following text.
• the oxysulphurized and fluorinated derivatives of formula (III) obtained according to the invention in particular an alkali metal salt of trifluoromethylsulphonate (CF 3 SO 3 R with R representing an alkaline cation), may be used for preparation of fluorinated derivatives of sulphonic acid, in particular trifluoromethanesulphonic acid, more commonly known as triflic acid (CF 3 SO 3 H).
• the subject of the invention is a process for the preparation of a fluorinated derivative of sulphonic acid of formula (IV)
• Ea representing the fluorine atom or a group having 1 to 10 carbon atoms selected from fluoroalkyls, perfluoroalkyls and fluoroalkenyls; in particular Ea representing the radical CF 3 ;
• a fluorinated derivative of sulfonic acid of formula Ea-SO 3 H where Ea is as defined above can be prepared according to the invention via at least the following stages:
• step (b1) adding to the reaction mixture obtained at the end of step (a1) of sulphonating an oxidizing agent, to obtain an oxysulphurized and fluorinated derivative of formula Ea-SO 3 R (III);
• the process of the invention is used to prepare trifluoromethanesulphonic acid (Ea represents the CF 3 radical).
• the compound of formula (I) used in step (a1) is an alkali metal salt of trifluorocarboxylic acid, in particular potassium trifluoroacetate (CF 3 COOK), and leads, in particular, to from step (cl) to trifluoromethanesulfonic acid (CF 3 SO 3 H).
• CF 3 COOK potassium trifluoroacetate
• step (cl) trifluoromethanesulfonic acid
• step (a1)) the conversion of the carboxylated compound of formula (I) during the sulfation reaction (step (a1)) is generally not complete.
• Acidification of the mixture of the compounds of formula Ea-SO 3 R and Ea-COOR leads to the mixture of the desired fluorinated acid derivative of sulfonic acid Ea-SO 3 H and the fluorocarboxylic acid Ea-COOH, for example to the mixture of Trific acid and trifluoroacetic acid (Ea represents CF 3 ).
• the fluorinated derivative of sulfonic acid Ea-SO 3 H can be isolated from the mixture obtained at the end of the acidification, for example by distillation.
• the fluorinated derivative of carboxylic acid Ea-COOH is advantageously recycled, for example in the process according to the invention.
• the sulfmation (a1) and oxidation (b1) steps are more particularly carried out under the conditions described above.
• the acidification is carried out via the steps of:
• substitution of the organic solvent S 1 by the solvent S 2 can be carried out by the following consecutive steps:
• the organic solvent SI is ⁇ , ⁇ -dimethylformamide (DMF).
• the organic solvent S2 with a boiling point greater than DMF, can for example be chosen from high-boiling alkanes, for example decalin (including the mixture of isomers), and aromatic derivatives which carry an electron-withdrawing group, for example orthodichlorobenzene (ODCB) or nitrobenzene.
• high-boiling alkanes for example decalin (including the mixture of isomers)
• aromatic derivatives which carry an electron-withdrawing group for example orthodichlorobenzene (ODCB) or nitrobenzene.
• Acidification of the compound of formula Ea-S0 3 R (III) (and carboxylated compound Ea-COOR (I) unreacted) in step (2) can be carried out by adding to the liquid mixture obtained at the end of the sulfuric acid step (1), in particular in the form of oleum.
• the sulfuric phase can then be extracted from the mixture obtained by phase separation after acidification, and the fluorinated derivative of sulfonic acid of formula (IV) isolated, for example by distillation of the sulfuric phase.
• the solvent S2 may advantageously be recycled for example in step (1).
• the fluorinated carboxylic acid derivative Ea-COOH is advantageously recovered for recycling, for example in the process of the invention.
• the acidification step may be carried out via the steps of:
• step () isolating the precipitated solid at the end of step () formed of the compound of formula Ea-SO 3 R (III) (and generally carboxylated compound Ea-COOR (I) unreacted);
• the organic solvent SI is ⁇ , ⁇ -dimethylformamide (DMF).
• the mixture S1 / S2 ' may be a homogeneous or heterogeneous mixture, preferably a homogeneous mixture.
• the solvent S2 ' may in particular be an alkane, a aromatic derivative, for example orthodichlorobenzene (ODCB) or toluene, a halogenated derivative, for example dichloromethane, an ether or an ester.
• the acidification of the solid in step (3 ') can be carried out by adding sulfuric acid or oleum.
• the fluorinated derivative of sulfonic acid of formula (IV) can then be isolated, for example by distillation of the sulfuric phase.
• the fluorinated derivative of carboxylic acid Ea-COOH is advantageously recovered for recycling, for example in the process of the invention.
• the fluorinated derivative of sulfonic acid Ea-SO 3 H obtained according to the invention can be advantageously converted into anhydride of formula (Ea-S0 2 ) 2 0 (V).
• the triflic acid obtained according to the invention can be used to access trifluoromethanesulphonic anhydride of formula (CF 3 -SO 2 ) 2 0 (triflic anhydride).
• the subject of the invention is a process for preparing an anhydride compound of formula (Ea-S0 2 ) 2 O (V), Ea representing the fluorine atom or a group having from 1 to 10 carbon atoms selected from fluoroalkyls, perfluoroalkyls and fluoroalkenyls, in particular Ea representing the radical CF 3 ;
• anhydride compound of formula (Ea-S0 2 ) 2 0 (V) in which Ea is as defined above can be prepared according to the invention via at least the following stages:
• step (b2) adding to the reaction mixture obtained at the end of step (i) of sulfmation of an oxidizing agent, to obtain an oxysulfurized and fluorinated derivative of formula Ea-SO 3 R (III); (c2) in the case where R is different from a hydrogen atom, acidifying the compound of formula (III) to obtain the fluorinated derivative of sulfonic acid Ea-SOsH; and
• the process of the invention is used to prepare trifluoromethanesulphonic anhydride (Ea represents the CF 3 radical).
• the compound of formula (I) used in step (a2) is an alkali metal salt of trifluorocarboxylic acid, in particular potassium trifluorocarboxate (CF 3 COOK), and leads, at the same time, to from step (d2) to trifluoromethanesulfonic anhydride ((CF 3 -SO 2 ) 2 O).
• the sulfination (a2), oxidation (b2) and optionally acidification (c2) stages are more particularly carried out under the conditions described above.
• the fluorinated sulphonic acid derivatives of formula Ea-SOsH, in particular triflic acid, and the anhydride compounds of formula (Ea-SO 2 ) 2 O, in particular triflic anhydride, can be used in various applications, especially as a catalyst.
• acid as protection group in organic synthesis, as synthon in the fields of pharmaceuticals, agrochemistry or electronics, as a salt for electronics, or as a component of an ionic liquid.
• the conversion rate of a reagent is the ratio of the molar amount of reagent consumed (transformed) during a reaction to the amount of initial reagent.
• the product yield from a reagent corresponds to the ratio of the molar amount of product formed to the molar amount of initial reagent.
• EXAMPLE 1 Preparation of potassium trifluoromethylsulfonate by oxidation of potassium trifluoromethylsulfinate by F -O 2 in ⁇ , ⁇ -dimethylformamide (DMF) i.
• TFAK potassium trifluoroacetate
• TFAK 20% by weight in the DMF-TFAK mixture.
• the reactor is equipped with a Raman probe to monitor the concentration in the medium of S0 2 dissolved, this probe is connected by optical fiber to the Raman spectrometer.
• the medium is stirred and heated to a temperature of 100 ° C.
• a quantity of 1.25 g of SO 2 gas is introduced continuously into the reactor through a micrometric control valve. to have a dissolved S0 2 concentration equal to 0.5% by weight, and an initial molar ratio S0 2 / TFAK of 0.059.
• the solution resulting from the sulfination reaction of potassium trifluoroacetate in DMF, prepared as described in point i. above, with a total weight of 267.19 g, is brought to 60 ° C, then added with an aqueous solution of hydrogen peroxide (mass content 30%) in three hours.
• the total amount of oxygenated water used is two molar equivalents relative to the content of potassium trifluoromethylsulfinate.
• the medium is then maintained at 60 ° C. for 2 hours and 51 additional minutes, during which monitoring by Raman spectrometry in situ makes it possible to follow the evolution of the species.
• a suspension of sodium percarbonate (20.8 g) in DMF is brought to 60 ° C., and then a solution resulting from the sulfonation reaction of potassium trifluoroacetate in DMF, prepared as described in Example 1 above, a total weight of 176.73 g is added to this medium in 2-3 hours.
• the reaction medium obtained after the oxidation according to Example 2 above is distilled under reduced pressure (160 mbar) and then added with decalin (200 ml, mixture of isomers). The distillation is continued by means of a Dean-Stark for regularly withdrawing the distilled DMF until the boiler is exhausted.
• the total mass of distilled DMF is 164.1 g.
• the sulfuric phase is then distilled under reduced pressure to yield 9.4 g of pure trifluoroacetic acid (CF 3 COOH) and 17.6 g of pure triflic acid (CF 3 SO 3 H), respectively.

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• 2014
  • 2014-12-09 FR FR1462098A patent/FR3029519B1/fr not_active Expired - Fee Related
• 2015
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